Hock immunization: A humane alternative to mouse footpad injections

Abstract

Footpad injection is a commonly used immunization method in mice. Being relatively easy to do with well-characterized lymphatic drainage, it has become a very useful immunization protocol to study local immune responses in draining lymph nodes. However, its disadvantages include use of only hind feet as a routine site of immunization since mice use their fore feet for food handling, and exacerbation of inflammation and swelling at the injection site leading to unrelieved pain and distress since feet are weight-bearing structures. With increasingly stringent Institutional guidelines for animal manipulations, there is increasing need for more humane protocols. A novel immunization protocol involving injection into the hock, the lateral tarsal region just above the ankle, a non-weight bearing structure draining to the same lymph node as the footpad, retains the advantages of footpad immunization without its drawbacks. This study, comparing immune responses between footpad and hock immunization in six different inbred mouse strains to two different protein antigens and a heat-killed bacterium, shows that hock immunization is a better alternative to footpad immunization, inducing comparable immune responses and being considerably more humane.

Antibody Response to Polyhistidine-Tagged Peptide and Protein Antigens Attached to Liposomes via Lipid-Linked Nitrilotriacetic Acid in Mice

“…Ten-week-old female BALB/c mice (Jackson Laboratories, Bar Harbor, ME) were housed in a UCSF specific-pathogen-free barrier facility. Animals (4 mice per group) received subcutaneous immunizations in alternating hind hocks on days 0 and 14 as described previously (23). Each injection contained 5 g OVA derivative or 25 g N-MPR derivative, 25 g MPL, and 1 mol lipid vehicle in 50 l sterile phosphate-buffered saline.…”

Covalent Linkage of HIV-1 Trimers to Synthetic Liposomes Elicits Improved B Cell and Antibody Responses

“…The efficiency with which various liposomes activate germinal center B cells was determined using 6-week-old female C57BL/6 mice (5 mice per group). Under isoflurane anesthesia, the mice were administered BG505 NFL trimers (10 g), either soluble or coupled to liposomes (27), subcutaneously in the hind legs by hock injections. One group of mice received plain liposomes as a negative control.…”

The purification and application of biologically active recombinant steroid cytochrome P450 21-hydroxylase: The major autoantigen in autoimmune Addison's disease

“…All animals were maintained under standard animal-housing conditions with ad libitum access to food and water. For priming of lymph node cells, mice were injected intradermally in the hindfoot hocks [18] with 5-10 mg of recombinant 21OH or 20 mg of 21OH-derived peptide in complete Freund's complete adjuvant. 21OH-derived peptides were synthesized as reported previously [13].…”